1. 18.06.2010BLM - MPP review, BLM Team, B. Dehning1 BLM – MPP review Hardware nonconformities and safety Equipment failures IP 3 signal cross talk IP 2 sanity check failures SEM signal Maximum of Acquisition Range Monitors with Filter Thresholds Global view Generation LSA developments MPP test remaining Audit

2. 9 IC with bad soldering Overview of failures (since Feb. 2010) 9 GOH with low power 1 damaged connector 6 CFC with noisy components 2 cards with bad soldering 6x optical receivers 1 x SRAM failed 18.06.20102BLM - MPP review, BLM Team, B. Dehning

3. System degradation analysis (I) System Component & Action: Ionisation Chambers – Sanity checks [once daily + 200 dur. tech. stop] – Check of all spares [ opening ~300 monitors] Current-to-Frequency Converter – Noise & Offset [technical stop] Optical links – Statuses & Errors [daily + weekly] Criticality:  Degradation in between of sanity checks: fast losses cannot correctly detected [reliability]  High noise/offset can give false dump requests [availability]  Lost packets provoke spurious dump requests [availability] 18.06.20103BLM - MPP review, BLM Team, B. Dehning

4. System degradation analysis (II) Future Actions (increase availability): Improve the analysis tools to achieve: – Better combination of results – Better display of results – Automation – Historical comparisons Large scale test of Optical Links: – Measure optical power of all links a few times – Understand if there is degradation over time – Understand if there is correlation with temperature 18.06.20104BLM - MPP review, BLM Team, B. Dehning

5. 18.06.2010BLM - MPP review, BLM Team, B. Dehning5 Shooting on TCLA in IR 7 Comparison of BLM Monitor Behaviour between IR 3 and IR 7 (I)

6. 18.06.2010BLM - MPP review, BLM Team, B. Dehning6 Shooting on TCLA in IR 3 (beam 1 and beam 2) The measured losses are equal in IP3 and in IP7 and they are equal for Left and Right side in IP3 → Functionality of the system is given and protection can be assured Comparison of BLM Monitor Behaviour between IR 3 and IR 7 (II)

7. 18.06.2010BLM - MPP review, BLM Team, B. Dehning7 Checked network structure HV on the front ends is stable, variation < 50 V (Unom=1.5kV) It can be not excluded that the effects come from signal cables Expected non-conformity in HV distribution Investigations and analysis ongoing, need more detailed studies Additional installations being done in order to investigate noise 1) Installation of batteries on spare channels: BJBAP.A6R3 Channel 7: connected battery with 1.5μA BJBAP.A8R3 Channel 7: connected battery with 1.5μA BJBAP.B8R3 Channel 7: connected battery with 1.5μA 2) Installation of cable + T splitters + HV resistors on spare channels: BJBAP.A6R3 Channel 8: HV via 100Mohm 15μA BJBAP.A8R3 Channel 8: HV via 100Mohm 15μA BJBAP.B8R3 Channel 8: HV via 100Mohm 15μA Beam tests and analysis pending Comparison of BLM Monitor Behavior between IR 3 and IR 7 (III) Actions being taken so far:

8. IP2 Sanity Check Nonconformity Observation: sequencer initiated sanity check does not start Consequence: timer reset is not done, no beam permit given Beam permit generation is independent of sequencer Non conformity is not safety critical 18.06.20108BLM - MPP review, BLM Team, B. Dehning

9. Resonance Crossing – SEM signal No signal from SEM expected: probable due to ionization in air, more investigations needed 18.06.2010BLM - MPP review, BLM Team, B. Dehning9

10. 18.06.2010BLM - MPP review, BLM Team, B. Dehning10 Maximum Values in the BLMs during Operation in 40 μs Calibration: 1mA = 200 counts * 1024 = 204800 BITS The counter is able to count up to: 255 counts * 1024 = 261120 BITS = 23.631 Gy/sec Absolut maximum (including ADC): 255 counts * 1024 + 1023 = 262143 BITS = 23.724 Gy/sec Restriction on LSA level (max. thresholds): 250 counts * 1024 = 256000 BITS = 23.168 Gy/sec Mostly 23.631 Gy/sec are measured

11. Filter Monitors Checking performance and behavior: 1)Check with beam that filters are installed at the defined channels (done) 2) Determination of rise time (time needed to collect 100% of the charges (use PM data) (missing for IP6) 3) Determination of ratio filter/non-filter amplitude, i.e. height of signal (partially done) 18.06.201011BLM - MPP review, BLM Team, B. Dehning Max @ 300 us Tau = 10ms

12. 18.06.2010BLM - MPP review, BLM Team, B. Dehning12 Thresholds for MB Monitors 239 MBB and MBA monitors (5 families according to position) All monitors have the same thresholds, no difference for positions 1,2,3 Monitor factor = 0.1

13. 18.06.2010BLM - MPP review, BLM Team, B. Dehning13 Thresholds for MQ Monitors 2361 MQ monitors (18 families according to position 1,2,3 in LSS, DS, ARC) Monitors in position 2,3 have the same thresholds and are ~ 30% smaller than for position 1 No difference for LSS, DS, ARC Monitor factor = 0.1

14. 18.06.2010BLM - MPP review, BLM Team, B. Dehning14 Thresholds for MQM Monitors 361 MQM monitors (12 families according to position 1,2,3 in LSS, DS) Thresholds in LSS: pos. 1 > pos. 2 (~90% smaller), pos. 3 at maximum Thresholds in DS : pos. 1 > pos. 2 (~30% smaller), pos. 3 same thresholds as in pos. 2 LSS pos.1 > DS pos.1 (~50% smaller) Monitor factor = 0.1

15. 18.06.2010BLM - MPP review, BLM Team, B. Dehning15 Thresholds for MQTL Monitors 24 MQTLH monitors (6 families according to position 1,2,3) No difference for position, non-linear energy dependence (change only above 3.5 TeV) Monitor factor = 0.1 Thresholds need to be reviewed and recalculated

16. 18.06.2010BLM - MPP review, BLM Team, B. Dehning16 Thresholds for MQXA Monitors 80 MQXA monitors (8 families according to position 1,2,3 and special positions) Thresholds in pos. 1 > pos. 2 (~70 % smaller) < pos. 3 (~25% higher) Thresholds in special positions are at maximum Monitor factor = 0.1

17. 18.06.2010BLM - MPP review, BLM Team, B. Dehning17 Thresholds for MQXB Monitors 64 MQXB monitors (4 families according to position 2,3) Thresholds in pos. 2 < pos. 3 (~25 % higher) Monitor factor = 0.1

18. 18.06.2010BLM - MPP review, BLM Team, B. Dehning18 Thresholds for MQY Monitors 108 MQY monitors (6 families according to position 1,2,3 in LSS) Thresholds in pos. 1 > pos. 2 (~90 % smaller), pos.3 at maximum Monitor factor = 0.1

19. Status of Threshold Settings NrElementsThresholds 1MBDetailed Geant4 and FLUKA simulations, Quench tests on LHC 2MQDetailed Geant4 simulations. 3MQXA, MQXB (triplets) Detailed FLUKA simulations (at 7 TeV only) 4B1.3B_MQXA B2.3B_MQXA Max. thresholds New simulations are done – to be revised 5MQYQuench Levels rescaled from MQ simulations, new Geant4 simulations and loss maps may be needed, monitors in position 3 have max. thresholds. Data analysis standalone magnet needed. 6MQM, MQML, MQM at 4.5 K Quench Levels rescaled from MQ simulations, analysis loss maps needed (as for MQY), Monitors in position 3 have max. thresholds 7MQTLHQuench Levels rescaled from MQ simulations (a setting error spotted, to be corrected asap) 8MBRB, MBRCBasic simulations for loss pattern generated by Wire Scanner, but thresholds are rescaled from MB 9MBX Quench Levels rescaled from MB + ECR's for over-injection issues More detailed analysis for over-injection needed 10CollimatorsEDMS 995569 + ECRs, systematic study of signal per lost proton needed Good knowledgeTo be checked with data More simulation Will be changed next Disconnected from BIS 18.06.201019BLM - MPP review, BLM Team, B. Dehning

20. 11TDIThresholds based on input from Brennan + analysis results Detailed simulations have been started (but no results yet) 12TCDMax. thresholds Need info from experts (who?) 13MSI/DDamage conditions agreed with Jan + Geant4 simulations (being revised now) 14MKI/DMax. thresholds Need info from experts 15Dump lineDisabled,i.e. disconnected from BIS Analysis needed in order to determine thresholds 16MQWThe same thresholds as for MSI/D 17MBWMax. thresholds (can they be re-scaled (BLM signal due to geometry) from MSI?) 18TANMax. thresholds Need info from experts 19Roman pots (XRP) Like TCT,TCLA thresholds + FLUKA simulations for BLM signal 20On missing magnet in DS (LYRA) FLUKA simulations 21DFBThe same thresholds as for MB Good knowledgeTo be checked with data More simulation Will be changed next Disconnected from BIS 18.06.201020BLM - MPP review, BLM Team, B. Dehning

21. 22TCSM + TCHS + TCAPA Disabled,i.e. disconnected from BIS, since element not installed 23All SEMDisabled,i.e. disconnected from BIS Analysis needed 24BSRTM +BGIThresholds as for MSI/D 25MBWMDMax. thresholds Need info from experts Good knowledgeTo be checked with data More simulation Will be changed next Disconnected from BIS 18.06.201021BLM - MPP review, BLM Team, B. Dehning

22. 18.06.2010BLM - MPP review, BLM Team, B. Dehning22 Threshold Generation Current: - Code written in C (object oriented source code, Macros to create thresholds) - Code needs to be debugged in detail and needs to be improved - For each family we use one specific Macro - Source code, macros and threshold files are stored in SVN with given version - Automatic versioning needs to be implemented - Documentation of all changes (stored in SVN): automatization needed - ECR for each change that needs to be signed by the responsible persons (needs further improvement) Planned: - Change to fully object oriented threshold code (C++ or python) - Implementing algorithms and parametrization on LSA level, thresholds generation directly in LSA Checks: - Maximum BITS (code, application, LSA level) - Decrease with energy and with integration time - Need more automatic procedures to keep human failures as small as possible

23. LSA Developments Internal LSA DB Constraints [improvement] – Most of them already reviewed – Need to add more complex/powerful constraints Internal LSA DB Check for disabled channels [available] – Based on monitor criticality and adjacent disabled channels – Each monitor is being tagged on its criticality – Current version blocks commits on rules violation – Needs review of the monitor tags (e.g. collimator monitors can be disabled atm) Roll-Back of commits – Complete :: using DB Retention functionality [available] Currently available max 24h after commit has been made Only by DB expert (i.e. CO/DM) – Partial :: using history tables [under development] Flags (masking, connection_to_BIS, …) Family (threshold values) Monitor (classification to family, other settings) 2318.06.2010BLM - MPP review, BLM Team, B. Dehning

24. Predefined Procedures (Audits) - what is not done Procedure/Implementation for generation of thresholds Direct dump not tested, high intensity needed (electrically done) Update of thresholds – two person procedure executed in the control room, enforced by program (will be implemted) 18.06.201024BLM - MPP review, BLM Team, B. Dehning MPS Aspects of the Beam Loss Monitor System Commissioning Management Procedure of the LM System Settings

25. MPS checks Beam Commissioning Tests (only those still pending) Interface of direct BLMs with the LBDS – Reduce the voltage setting of the abort threshold. – Dump the injected beam on the collimator TCDQ and TCSG (with local bump)  2 hours and 2 accesses Provoked quench for transient losses – ‘recovering quench’ detected with the nQPS – The losses are recorded and compared to the expected quench level  1 hour/magnet type = 4 hours Provoked quench for steady-state losses – ‘recovering quench’ detected with the temperature sensors – The losses are recorded and compared to the expected quench level  1 hour/magnet type = 4 hours More info: https://espace.cern.ch/LHC-Machine-Protection/

26. External Audit Review will seek to: assess the adequacy of the overall BLM system design with a focus on the programmable parts identify possible weaknesses in the programmable parts of the mission-critical BLM suggest activities that could increase the level of confidence that the programmable parts of BLM system performs as intended suggest potential improvements of the BLM provide a general comparison of the BLM with approaches in industrial systems. DateResponsibleDeliverable 16 th August 2010CERNDelivery of project documentation 6 th September 2010CSL/CERNFinalization of site-visit agenda 13 th to 16 th September 2010CSL/CERNOn-Site visit - 4 full days 18 th October 2010CSLDelivery of written report 18.06.201026BLM - MPP review, BLM Team, B. Dehning